Publications

To assess the adaptation of the left ventricle to a chronic pressure overload we used echocardiography to study 18 patients with left ventricular hypertrophy caused by systemic arterial hypertension. Increased values for either posterior wall or interventricular septal thickness or both confirmed the presence of left ventricular hypertrophy in all patients and an increase in the average wall thickness to radius ratio was consistent with the development of concentric hypertrophy. No patient had clinical evidence of ischaemic heart disease. Ejection phase indices of left ventricular performance (mean Vcf, fractional per cent of shortening, normalised posterior wall velocity, and ejection fraction) were within the normal range in the basal state in 16 of the 18 patients. The hypothesis is advanced that patients with concentric left ventricular hypertrophy resulting from systemic arterial hypertension usually have normal left ventricular performance in the basal state because values for wall stress remain within the normal range. We conclude that the hypertrophic response to a chronic increase in systemic arterial pressure does not per se result in depression of the basal inotropic state of the left ventricle.

In 38 patients undergoing elective coronary arterial bypass graft surgery, the radiographic dimension of the left side of the heart was determined and echocardiographic studies were performed before and after surgery. On the plain chest x-ray film one week after surgery, all patients showed an increase in the size of the left side of the heart, which usually was not accompanied by an increase in the echocardiographic left ventricular end-diastolic dimension; however, in 25 patients, pericardial fluid was detected soon after surgery, which would explain the enlarged cardiac silhouettes. Several months after surgery, the radiographic size of the heart returned to the preoperative value in most patients, and pericardial fluid was no longer demonstrated on the echocardiogram. Thus, pericardial fluid frequently is found in the first week following coronary arterial bypass graft surgery and may give the impression of increased cardiac size on plain chest x-ray films; however, echocardiographic studies provide a more accurate estimate of left ventricular size and reveal the presence of pericardial effusion.